Epidemiological trends of dengue in mainland China, 2005–2015

Objective: To explore the epidemiological trend of dengue in mainland China. Methods: Data on dengue cases reported from 2005 to 2015 were collected, and epidemiological trends, including average age, occupation, seasonal distribution, and interval from illness onset to confirmation, were analyzed using SPSS 19.0 and R 3.1.1. Results: A total of 59 334 dengue cases were recorded in China during the years 2005–2015. Most dengue cases occurred in individuals aged between 21 years and 50 years. Of note, the median age of dengue cases did not show a trend towards becoming younger; the median age was significantly older than that of cases in dengue endemic areas. The proportion of cases occurring during September and October was higher in 2012–2015 than in 2005–2011. The number of affected provinces ranged between 10 and 27 and the number of affected counties ranged between 42 and 415. The median time from illness onset to confirmation of dengue decreased sharply in 2015, indicating that comprehensive measures have been taken in mainland China. Conclusions: Although the number of dengue cases has increased and the affected areas have expanded in recent years, dengue is still an imported disease and does not present an endemic trend in mainland China